Disturbance regimes,resilience, and recovery of animal communities and habitats in lotic ecosystems

Disturbance regime is a critical organizing feature of stream communities and ecosystems. The position of a given reach in the river basin and the sediment type within that reach are two key determinants of the frequency and intensity of flow-induced disturbances. We distinguish between predictable and unpredictable events and suggest that predictable discharge events are not disturbances. We relate the dynamics of recovery from disturbance (i.e., resilience) to disturbance regime (i.e., the disturbance history of the site). The most frequently and predictably disturbed sites can be expected to demonstrate the highest resilience. Spatial scale is an important dimension of community structure, dynamics, and recovery from disturbance. We compare the effects on small patches (⩽1 m²) to the effects of large reaches at the river basin level. At small scales, sediment movements and scour are major factors affecting the distribution of populations of aquatic insects or algae. At larger scales, we must deal with channel formation, bank erosion, and interactions with the riparian zone that will affect all taxa and processes. Our understanding of stream ecosystem recovery rests on our grasp of the historical, spatial, and temporal background of contemporary disturbance events.     

Biogeochemical cycling constraints on stream ecosystem recovery

In systems where production is limited by the availability of a nutrient, nutrient input to and recycling within the system is related to the resilience, or speed of recovery, of a system to its steady state following a disturbance. In particular, it is shown that the return timeT _s of the system to steady state, or the inverse of the resilience, is approximately equal to the mean turnover time of the limiting nutrient in the system. From this relationship, it is possible to understand and predict how various properties of food webs and their environments affect resilience. These properties include nutrient input rate, loss rate, size of the detritus compartment, and trophic structure. The effects of these properties on resilience are described by using simple mathematical models. To test model predictions, experimental studies of the response of periphyton-dominated stream ecosystems to disturbance are being conducted on a set of laboratory streams in which nutrient inputs and grazing intensity are regulated at different levels. In streams without snail grazers (low-grazed streams), 90% recirculation of stream water to reduce nutrient inputs resulted in longer turnover times (T _r ) of phosphorus within the stream compared with once-through flow. However, in streams with snail grazers (high-grazed streams), there were no differences in phosphorus turnover time between once-through and partially recirculated treatments. Results on the rate of recovery of periphyton from a flood/scour disturbance to each stream partially support the model prediction of a positive relationship between ecosystem return time (T _s ) and nutrient turnover time (T _r ) within the streams.     

A THEORETICAL FRAMEWORK OF FLOOD INDUCED CHANGES IN URBAN LAND VALUES1

ABSTRACT: By integrating literature from flood hazard research and urban economics a theoretical structure is developed to explain changes in residential land values following flood events. The negative aspects of the flood hazard are shown to be capitalized in the value of the property. It is further suggested that land values (i.e., capitalization) will vary both spatially across the floodplain and temporally depending on the frequency, severity and spatial characteristics of the flood event. Previous work in this area has not addressed the capitalization process explicitly and has not specifically examined the ability of the land market to recover. This may account for the contradictory findings in the published literature.     

Understanding Dispute Resolution Processes for American and Australian Public Wildlands: Towards a Conceptual Framework for Managers

/ The last 20 years have seen the successful application of environmental dispute resolution processes, where people voluntarily negotiate toward mutually acceptable solutions, to many environmental disputes. The effects of contextual influences, such as the number of parties and presence of deadlines, on outcomes are known and frequently described. Less well documented and understood are the interaction processes themselves. This paper draws on two case studies to develop a conceptual framework describing these processes. Disputes associated with management planning for the Bob Marshall Wilderness Complex in the United States and Fitzgerald River National Park in Australia provided the cases. The conceptual framework derived had eight sequential stages: (1) joint definition of problems, (2) uncertainty about what to do, (3) agreement on group procedures, (4) realization of interdependence, (5) enthusiasm about collective possibilities, (6) commitment to working together, (7) consolidation of the group, and (8) implementation of a resolution. The framework provides new insights for managers of public wildlands, especially the need for varying but ongoing managerial involvement in dispute resolution processes. High levels of involvement and influence are essential at the beginning in problem definition and group procedure design and at the end in implementing resolutions. Conversely, agency members must be willing to exert less influence, while still being involved and committed to collective purposes, during the middle stages. Also apparent from the conceptual framework is the importance of developing shared understandings and of allowing sufficient time for understanding to develop, if successful resolution is to be achieved. KEY WORDS: Environmental dispute resolution; Conceptual framework; Public wildlands; Shared understandings; Australia     

Small cetacean bycatch as estimated from stranding schemes: The common dolphin case in the northeast Atlantic

Death in fishing gear of non-target species (called ‘bycatch’) is a major concern for marine wildlife, and mostly worrying for long-lived species like cetaceans, considering their demographic characteristics (slow population growth rates and low fecundity). In European waters, cetaceans are highly impacted by this phenomenon. Under the Common Fishery Policy, the EC 812/2004 regulation constitutes a legal frame for bycatch monitoring on 5–10% of fishing vessels >15 m. The aim of this work was to compare parameters and bycatch estimates of common dolphins (Delphinus delphis) provided by observer programmes in France and UK national reports and those inferred from stranding data, through two approaches. Bycatch was estimated from stranding data, first by correcting effectives from drift conditions (using a drift prediction model) and then by estimating the probability of being buoyant. Observer programmes on fishing vessels allowed us to identify the specificity of the interaction between common dolphins and fishing gear, and provided low estimates of annual bycaught animals (around 550 animals year⁻¹). However, observer programmes are hindered by logistical and administrative constraints, and the sampling scheme seems to be poorly designed for the detection of marine mammal bycatches. The analyses of strandings by considering drift conditions highlighted areas with high levels of interactions between common dolphins and fisheries. Since 1997, the highest densities of bycaught dolphins at sea were located in the southern part of the continental shelf and slope of the Bay of Biscay. Bycatch numbers inferred from strandings suggested very high levels, ranging from 3650 dolphins year⁻¹ [2250–7000] to 4700 [3850–5750] dolphins year⁻¹, depending on methodological choices. The main advantage of stranding data is its large spatial scale, cutting across administrative boundaries. Diverging estimates between observer programmes and stranding interpretation can set very different management consequences: observer programmes suggest a sustainable situation for common dolphins, whereas estimates based on strandings highlight a very worrying and unsustainable process.     

Which “fairness”, for whom,and why? An empirical analysis of plural notions of fairness in Fairtrade Carbon Projects,using Q methodology

Fairness is a relative concept with multiple, subjective and competing notions of what it is, how to achieve it, and for which beneficiaries. Fairtrade International's collaborative efforts to develop a standard to certify Fairtrade Carbon Credits (FCCs) brought together multiple stakeholders in a deliberative context. This paper uses Q methodology to empirically assess the notions of fairness this wider consultation group held. Three distinct ‘factors’ (or perspectives) are identified, and discussed in relation to a multi-dimensional framework for exploring fairness. The first factor prioritises development delivered through organisations, participation in decision-making and use of minimum prices to adjust trade imbalances. The second factor conceptualises a non-exclusive approach maximising generation and sales of FCCs, involving a commodity chain where everyone performs their optimum function with financial transparency and information-sharing to facilitate negotiations. The third factor involves minimising intervention, allowing carbon commodity chains and project set-ups to function efficiently, and make their own adjustments to enhance benefits access and quality received by beneficiaries. The three factors reflect debates within carbon and fair trade spheres about who should be playing which roles, who should be accessing which benefits, and how people should be supported to interact on an uneven playing field. Communicating findings to standards organisations enables a more open and inclusive policy process. Our research provides a critical reflection on these plural notions of fairness, identifying areas of (dis)agreement within the FCC dialogue, and provides a wider, yet manageable, set of inputs for supporting the FCC process during its inception and subsequent implementation. Clearer definitions of “fairness” are also useful for standards organisations in reviewing ex post whether “fairness” goals have been met.     

A new tool to map the major worldviews in the Netherlands and USA,and explore how they relate to climate change

For addressing climate change, public support for changes in policy is needed, as well changes in individual lifestyles. Both of these appear to be intimately related with people’s worldviews. Understanding these worldviews is therefore essential. In order to research and ‘map’ them, we translated the theoretical ‘Integrative Worldview Framework’ (IWF) into an empirical, quantitative approach. We constructed a worldview-scale aiming to distinguish between four major worldviews – labeled traditional, modern, postmodern, and integrative – and explored their interface with opinions and behaviors with respect to climate change. The survey was conducted with representative samples of citizens in the Netherlands and the USA (n = 527 and n = 556). The hypothesized worldviews were found in the data with a reasonable degree of reliability, especially in the Dutch sample. We also found consistent relationships between these worldview-clusters and a range of opinions, political priorities, and behaviors. In both countries postmoderns and integratives displayed significantly more concern about climate change as well as more sustainable behaviors, compared with moderns and traditionals. The implications of these findings for environmental policy and social science are noteworthy.     

Measuring the adaptation gap: A framework for evaluating climate hazards and opportunities in urban areas

Urban areas are increasingly seen as having distinct need for climate adaptation. Further, as resources are limited, it is essential to prioritize adaptation actions. At the municipal scale, we suggest that priorities be placed where there is a gap between adaption need and existing adaptation effort. Taking Seattle, USA, as an example, we present this gap in terms of four categories of adaptation options (no-regret, primary, secondary, and tertiary) for the three primary urban hazards—flooding, heat wave, and drought. To do so, we first establish current adaptation need by identifying and categorizing adaptation options. Next, we consider for each option the number of hazards addressed and benefit to and beyond climate adaptation, the projected magnitude of the hazards addressed, the projection’s uncertainty, and the required scale and irreversibility of investment. Third, we assessed Seattle’s current adaptation efforts by reviewing adaptation plans and related materials. Finally, we identify the distance or “gap” as the proportion of adaptation options not identified by existing adaptation plans.For Seattle, we categorized seven options as no-regret adaptation, five as primary, two as secondary, and three as tertiary. Each level’s adaptation gap highlights significant opportunities to take steps to reduce climate risks in key areas.     

A framework for evaluating flood risk governance

Calls to strengthen flood risk governance are echoed across Europe amidst a growing consensus that floods will increase in the future. Accompanying the pursuit of societal resilience, other normative agendas relating legitimacy (e.g. accountability and public participation), and resource efficiency, have become attached to discussions concerning flood risk governance. Whilst these represent goals against which ‘success’ is socially and politically judged, lacking from the literature is a coherent framework to operationalise these concepts and evaluate the degree to which these are achieved. Drawing from cross-disciplinary and cross-country research conducted within the EU project STAR-FLOOD, this paper presents a framework for evaluating the extent to which flood risk governance arrangements support societal resilience, and demonstrate efficiency and legitimacy. Through empirical research in England, this paper critically reflects on the value of this approach in terms of identifying entry points to strengthen governance in the pursuit of these goals.     

Adaptive governance to typhoon disasters for coastal sustainability: A case study in Guangdong,China

Globally, more people and assets are concentrated on the limited coastal plains where they are exposed to frequent disasters, such as typhoons, rainstorms and floods that often result in tremendous casualties and economic losses. Based on the causal analysis of the historical typhoon cases in the Guangdong Province of China, this study indicates that structural measures alone are not sufficient to resist and offset the impacts caused by typhoon disasters. Additionally, structural measures are unsustainable due to their high investment and low security. Adaptive governance, which uses non-structural measures and resilience building, is a feasible and cost-effective strategy for responding to the cascading effects of typhoon disasters. Multi-stakeholder participation and vertical–horizontal coordination are essential for providing adaptive governance to typhoon disasters. A risk-sharing model was put forward by bringing together the government, insurance companies and victims. Furthermore, a favorable atmosphere for public participation in disaster risk reduction can be fostered and should be a long-term adaptation strategy. The views and frameworks of adaptive governance provide policy makers with insights on coastal disaster risk management within the broader context of climate change.